XsltHelper.java

/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community License, Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of the License
 * at:
 *
 *   http://opensource.org/licenses/ecl2.txt
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations under
 * the License.
 *
 */
package org.opencastproject.coverimage.impl.xsl;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.text.WordUtils;

/** Helper class to use within the XSLT transformation */
public final class XsltHelper {

  private static final String LINE_SEPARATOR = "<newline>";

  private XsltHelper() {
    // Utility classes should not have a public or default constructor.
  }

  /**
   * Splits a string into several lines, depending on the maximum allowed characters per line and returns the desired
   * line.
   *
   * @param text
   *          Text to split up
   * @param maxChars
   *          maximum allowed characters per line
   * @param line
   *          line number to return (starting by 1)
   * @param isLastLine
   *          whether this is the last line used to represent the string. If so, the string will be abbreviated using
   *          ellipsis in case the text cannot be represented by the given number of lines
   * @return the line or null if the given text is null, the line number is less than 1 or if the desired line does not
   *         exist
   */
  public static String split(String text, int maxChars, int line, boolean isLastLine) {
    if (text == null || line < 1) {
      return null;
    }

    if ((maxChars > text.length() && line == 1) || maxChars == 0) {
      return text;
    }

    String textWithSeparator = WordUtils.wrap(text, maxChars, LINE_SEPARATOR, true);
    String[] lines = textWithSeparator.split(LINE_SEPARATOR);

    if (lines.length >= line) {
      if (isLastLine && (lines.length > line) && (maxChars > 3)) {
        /* Abbreviate lines using ellipsis. Because of word wrapping, the line length can be less than maxChars.
           That case is covered by first appending the ellipsis and then applying abbreviate */
        String lastLine = lines[line - 1] + "...";
        return StringUtils.abbreviate(lastLine, maxChars);
      } else {
        return lines[line - 1];
      }
    } else {
      return null;
    }
  }
}